This invention relates to a wheel rim assembly and more particularly to a new and improved locking ring assembly for a separable wheel structure.
Wheel assemblies, and more particularly wheel assemblies provided for aircraft, are well known. One such wheel assembly is a two piece structure that utilizes a wheel base (with an integral wheel rim member) and a separable wheel rim member that is secured to the wheel base by a locking ring. The locking ring is split to enable the locking ring to be circumferentially expanded and installed onto the wheel assembly. The base has a groove for receiving the locking ring and the separable wheel rim member has a recessed ledge that circumscribes the locking ring when the wheel rim member is urged axially outwardly against the locking ring. The ledge functions to retain the locking ring in the groove as long as the wheel rim member is held axially against the locking ring.
A pneumatic tire is mounted on the wheel base followed by the wheel rim member and finally by the locking ring. When the tire is inflated, the inboard and outboard beads are urged relatively axially apart to seat the separable wheel rim member against the locking ring.
In the event of a loss of inflation pressure, such as a tire blowout, the separable wheel rim member may move axially inwardly such that the locking ring no longer is surrounded by the ledge of the separable wheel rim member. This may allow the locking ring to be thrown off of the wheel rim by the high centrifugal forces which are present.
Various devices and methods have been employed to prevent the locking ring from being thrown from the wheel assembly. One such method is to thread opposite ends of a lock wire into respective holes in the terminal ends of the locking ring and then twist the ends of the lock wire together. Although this method is commonly used in the industry, it can be tedious and inconvenient. In another prior art approach, a lock wire is used to retain a buckle which, in turn, connects the terminal ends of the locking ring. Although an acceptable method in retaining the locking ring, the buckle and the ends of the lock wires remain directly exposed to the rigors of the environment.
The present invention provides a locking ring assembly for a wheel rim assembly. The locking rim assembly includes a locking ring, a retaining key inserted into recesses in the terminal ends of the locking ring to maintain the terminal ends adjacent one another, and a clip for securing the retaining key relative to the terminal ends of the locking ring.
According to an aspect of the invention, a locking ring assembly includes a locking ring, a retaining key and a clip. The locking ring has a transverse split defining circumferentially opposing terminal ends that include respective radially outwardly opening recesses. The retaining key has opposite end portions respectively received and circumferentially retained within the radially outwardly opening recesses in the respective terminal ends of the locking ring, thereby holding the terminal ends of the locking ring adjacent one another. The clip engages and radially restrains the retaining key in the recesses, i.e., restrains the retaining key from radially outward movement out of the recesses.
The retaining key preferably includes transversely enlarged end retainer portions and a reduced width bridge portion therebetween, and the recesses include corresponding enlarged end portions for radially receiving the respective enlarged end retainer portions, and reduced width portions for radially receiving the reduced width bridge portion. The terminal ends of the locking ring may be circumferentially spaced apart when installed on a wheel base and the bridge portion may span the space between the enlarged end recessed portions. One or both of the enlarged end retainer portions of the retaining key may be smaller in circumferential extent than the respective enlarged end portion of the recess to which it corresponds, such that the retaining key is restrained for limited circumferential movement relative to the locking ring.
The clip preferably is a spring clip including a first portion engaging the locking ring and a second portion engaging the retaining key, which first and second portions are resiliently biased towards one another. The clip may be formed from a continuous length of wire having an intermediate section forming the second portion and opposite end portions forming the first portion. Also, the opposite end portions may be disposed in respective axially extending holes in the locking ring and the intermediate section may extend over the retaining key. Further, the intermediate section of the clip may be reversely bent on itself to form a pair of legs joined by a connecting portion, and the connecting portion may be bent radially to overlap an axial side surface of the retaining key, such that the clip is retained in place. Still further, the recesses may include corresponding reduced width recessed portions which together radially receive the reduced width bridge portion, while the axial holes open to the reduced width recessed portions and the opposite end portions of the clip extend through the axial holes and over the bridge portion of the retaining key to prevent radially outward movement of the retaining key from the recesses.
According to another aspect of the invention, a wheel rim assembly includes a wheel base, a separable wheel rim member, and a locking ring assembly as set forth above. The locking ring is received within a groove in the wheel base to secure the wheel rim member to the wheel base.
According to a further aspect of the invention, there is provided a method of installing a locking ring in a wheel base, comprising seating the locking ring in a groove in the wheel base, the locking ring having a transverse split defining circumferentially opposing terminal ends, the terminal ends including respective radially outwardly opening recesses, inserting a retaining key having opposite end portions into the respective outwardly opening recesses, axially inserting a first portion of a clip in an axial hole in the locking ring, flexing a second portion of the clip relative to the first portion of the clip, the first and second portions being biased towards one another, extending the second portion over the retaining key, and releasing the second portion, whereby the second portion engages the retaining key to restrain the retaining key from radially outward movement from the recesses.
According to a further aspect of the invention, there is provided a locking ring assembly for a wheel rim assembly, the locking rim assembly including a locking ring, a retaining key and a resilient push-on clip. The locking ring has a transverse split defining circumferentially opposing terminal ends, and the terminal ends have recesses. The retaining key has opposite end portions that are inserted into the recesses and circumferentially captured in the recesses. The resilient push-on clip has a first arm for engaging at least one terminal end of the locking ring and a second arm resiliently biased towards the first arm for engaging and holding the retaining key in the recesses.
The invention also provides a novel locking ring, retaining key and clip, as above defined.
The foregoing and other features of the invention are hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawings setting forth in detail illustrative embodiments of the invention, such being indicative, however, of but a few of the various ways in which the principles of the invention may be employed.